Cleaning large metal surfaces with abrasive blasting material (abrasive grit material) by abrasive blasting (or pressure blasting), such as by sandblasting, bead blasting, etc., is well known in the related art. The most commonly used type of abrasive blasting media currently used is silica sand, fine glass beads, steel shot, steel grit, stainless steel shot, cut wire, grit or similar sized pellets, etc. It is possible to repeatedly use the same abrasive blasting material (or media) several times, if the abrasive blasting material is properly cleaned between each use.
One consequence of the abrasive blasting process on the abrasive blasting materials resulting from high velocity impacting on steel surfaces being cleaned causes them to abrade and generate contaminants such as dirt, paint, mill scale, and rust from the treated surface. At the same time a certain amount of fractured, fine abrasive particles (dust) is also produced.
Various types of devices for cleaning and reclaiming spent abrasive blasting media are available in the related art. Typically, in such a device, the used abrasive blasting media is vacuumed up and carried in an airstream to a cleaning and separating device. Lightweight contaminants are removed by air-washing, while large particulate contaminated material is separated by a separating device.
While known devices for cleaning and reclaiming spent abrasive blasting media have proven to be acceptable for various abrasive blasting media cleaning and reclaiming applications, such devices are nevertheless susceptible to improvements that may enhance their performance, applicability, cost and attractiveness. With this in mind, a need exists to develop an improved screening device and method for separating and recovering spent abrasive blasting material for reuse that advances the art.